Alkyl aromatic hydrocarbon emulsion lubricant for metal rolling



United States Patent 3,432,434 ALKYL AROMATIC HYDROCARBON EMULSION LUBRICANT FOR METAL ROLLING Eldon L. Armstrong, Mullica Hill, and Robert H. Davis,

Pitman, N.J., assignors to Mobil Oil Corporation, a corporation of New York No Drawing. Filed May 19, 1967, Ser. No. 639,639 U.S. Cl. 252--49.5 12 Claims Int. Cl. 010m 3/10, 3/04 ABSTRACT OF THE DISCLOSURE Emulsions containing 5% to 99% by weight of water and 95% to 1% of an alkyl aromatic composition provide effective non-staining roll oil lubricants, especially for rolling nonferrous metals, such as aluminum alloys. The aromatic compounds include those having from 1 to 3 rings with the number of alkyl groups ranging from 1 up to the available number of substitutions on the rings, each alkyl group having 3 to 20 carbon atoms. The compounds contain a total of from 12 to 40 carbon atoms.

BACKGROUND OF THE INVENTION This invention relates to an emulsion lubricant for metal-rolling operations, and in particular it relates to a method of cold rolling non-ferrous metals, particularly aluminum alloys, using aqueous emulsions containing aromatic lubricants.

DESCRIPTION OF THE PRIOR ART British Patent No. 892,565 discloses method of rolling metals using aromatic hydrocarbons. French Patent No. 980,058 discloses specific alkylated aromatic hydrocarbons for use in metal-rolling. These patents deal with use of the hydrocarbons in a neat form, stating that they possess non-staining and load carrying characteristics. The loadcarrying and non-staining requirements for roll oil lubricants are important in metal-rolling operations. However, of equal importance with these criteria is the cooling efficiency of roll oils. Metals exposed to extreme pressures under high temperature, particularly in the cold reduction process, may suffer undesirable changes in metallurgical characteristics. Moreover, use of oils that are unable to cool uniformly can cause variances in roll diameter and inconsistencies in the gauge of the finished piece. As a result, the operations may have to be repeated or the metals must be scrapped. Until now, no lubricant which has a high cooling efiiciency and which is also nonstaining has yet been found for cold-rolling operations on aluminum alloys.

SUMMARY OF THE INVENTION It has now been found that oil-in-water. or water-in-oil emulsions containing from 5% to 99% by weight of water and 95% to 1% by weight of an alkyl aromatic compound having 12 to 40 carbon atoms of the formula:

wherein Ar is an aromatic hydrocarbon of 1 to 3 aromatic rings, R is alkyl of 3 to 20 carbon atoms and n is 1 up to the number of available positions of Ar, preferably 1 to 2. Ar may include phenyl, diphenyl, naphthalene or anthracenyl. The R groups may be the same or different when n is greater than 1. The preferred number of alkyl carbon atoms for R is in the range of 6 to 16; thus, when n is l, the smallest R group is preferably hexyl.

The emulsions of this invention may be prepared by adding the emulsifiers to the alkylated aromatic compound and then combining this mixture with the appropriate quantity of water using known emulsifying techniques.

Generally, simple agitation is sufiicient. The water concentration ranges from 5% to 99%: 5% to about 50% for water-in-oil emulsions and 50% to about 99% for oil-in-water emulsions. The oil-in-water emulsions are excellent coolants. They retain enough lubricity to permit satisfactory rolling operations, and they are non-staining. When the organic compound is the preponderant component, the resulting water-in-oil emulsion has excellent load-carrying ability and better cooling properties than the neat or unemulsified compounds and these emulsions are relatively non-staining.

The emulsifiers used in this invention are not limited to specific classes. Most commercial emulsifiers are useful in preparing the emulsion lubricants of this invention, including cationic, anionic, and nonionic. Oil-in-water emulsions are prepared from emulsifiers having a hydrophilic-lipophilic balance (HLB) number of over 6, while water-in-oil emulsions are made from 2 to 6 HLB emulsifiers. The effect of this HLB number is discussed in more detail in US. Patent No. 3,213,024. Anionic emulsifiers include alkali and alkaline earth metal and amine sulfonates, phenates and phosphates as well as soaps derived from fatty acids. Nonionic emulsifiers include alkylene oxide adducts of C -C -alkyl phenols, and of polyols and ethers containing 2 to 12 moles of oxide. High temperature stabilizers may also be present, to maintain the emulsions during use. The nonionic stabilizers include alkylene oxide adducts of C -C acids, amides, and esters. Adducts of ethylene oxide, also hereinafter referred to as ETO, are of particular interest. Preferred agents are ethoxylated nonyl phenol (9 to 10 moles of ETO) and ethoxylated oleyl ether (2 moles of ETO), for oil-in-water systems and ethoxylated sorbitan monooleate (over 2 moles of ETO) for water-in-oil systems. The term ETO represents ethoxy groups.

The emulsions of this invention are exceptionally adapted to the cold-rolling of nonferrous metals, such as aluminum. Upon exposure to the 600 to 650 F. temperatures used in annealing aluminum to relieve coldrolling stress, the roll oil lubricants in the past have formed objectionable residues or lacquers on the metal which made the finished metal unfit for sale. Mineral oil is susceptible to this form of breakdown. Even certain alkyl aromatic compounds in the neat form cannot withstand prolonged periods at 600 F. It has been found that many of these too can break down and leave stains. Surprisingly the emulsions of this invention are almost completely non-staining,

The preferred alkyl aromatic contains, 1 or 2 6- membered rings. The alkyl side chains attached to the aromatic nucleus may contain 3 to 20, and preferably 6 to 16 carbon atoms. However, the total number of carbon atoms in the molecule should not be less than 12 and should not exceed 40. Dodecyl benzene and monononyl naphthalene are the most preferred since these substances are readily obtained in commercial amounts. Mixtures of the alkyl aromatic compounds may also be used. Moreover, the emulsions of this invention have been found to 'be so effective that even a minor proportion of the mineral oil can be tolerated therein. A preferred concentration of.mineral oil for such compositions is in the range of from 1% to 30% by weight of the total of the oil phase.

The following examples illustrate the invention more clearly.

Example 1 Oil-in-water emulsions are prepared from the following emulsifier package: 50% by weight of ethoxylated nonyl phenol (9 to 10 moles of ETO), 40% by weight of ethoxylated oleyl ether (2 moles of ETO), and 10% by weight of cyclohexanol. This package is added to a series 3 of oils, including the alkyl aromatic compounds, at a concentration of 5% by weight at 120 F. The resulting soluble oil is combined with water in a weight ratio of 1 part soluble oil per 8 parts of water. Known techniques to form the emulsion are used in preparing each of the emulsion sam le 5 combining a mixture of 87.5 parts by weight of base Example 2 medium, parts by weight of pelargomc acid and 2.5 parts by weight of an ethoxylated tallow amine (2 moles Water-rn-oil emulsions are prepared by adding 0.25% by weight of polyoxyethylene sorbitan monooleate and 5:83 The Weight mm of the 011 mixture to 3 8. 23 35 2222332? g g ggig g i ig s i gf 10 In the internal thread forming test the emulsions are ase 4 t th 1 M t 1 an used to lubricate the threading of a hole in metal without a welg t mm) of Par 5 o C so u e 1 0 p cutting the metal. The metal work piece is 7075 aluminum, 0 gz i of Examples 1 and 2 are tested in an the hole size is 0.228 inch. The thread former is rotated aluminum stain test. A series of cold-rolled aluminum g: g gg fi g i 'g gi z y f torque is rated plates are cleaned and dried. Over the surface is spread 0.8 ml. of the sample emulsion as a coating. The plates E=l00 A/B percent 2 21 2 223 f gg g fig l gf ig g xfig g E is efficiency, A is the average torque of any standard and observed ior staining Five standard plates are used refere-nce and B is the average Porque of samp 1e test 011. A result of 100 or below indicates that the sample as the companson the test samples,bemg matched with oil is equal to or worse than the reference standard. The i if q q g i 232? 252 s to standard used is a commercial mineral oil-in-water emula m mg es n s a m 1 sion. The results are tabulated in Table 3.

The results for the oil-in-water emulsions are tabulated in Table 1. Those for the water-in-oil emulsions are TABLE 3 tabulated in Table 2.

Table 1 Base Oil Parts by Weight E M 1on 87.5 103 Base 1 Stain mung l1. D3323] Benzene 87.5 131 Dodecyl Benzenea 1 I llglolontirgl Naphthalen 143 811 D8 E23 3212351 liliilialzaa' i m a; 0TB E2; 31 231 g fi g 1 Paraffinic 011,35 sus at 100 F. (f) Mineral Oil 4 35 lBmnched chain; Sp. g at FJGO. F. 03639; Bromine It 1s evident from the above results that the emulsion No .s0t.11i. ht h i t 60 F 0 8 0 7 C 38 7 lubricants of this lnventlon can be successfully employed mg C an? i 0 in the rolling of metals particularly when the process ,6.7 .2 C lklh' o o ciilfiiffiqe to 25 ;f b3 wz i n t dt dingn y l im nthalene. includes an anneahng step of about 600 to 650 F.

Zg'gfgg gg g iggfii ggg f; S SUS at F 40 The scope of the invention is not limited by the specific T p d 1 b d examplespresented, but may include all variations andhe a 011 of ltefns and e ave a teste as modifications, which become manifest to those skilled lll c arms. pounds when used alone are unfit as a lubricant. We claim:

Table 2 1. An emulsion lubricant suitable for the rolling of Base on: Stain rating non-ferrous metals consisting essentially of about 5% to (g) nodecyl benzene 1 1 99% by weight of water and 95% to 1% by weight of an (11) Mononyl naphthalene 3 2 alkyl aromatic hydrocarbon, having from 1 to 3 aromatic (i) Mineral oil 5 5 rings wherein the alkyl groups contain from 3 to 20 caru bon atoms per group, and the total number of carbon lfi f cham at 60 F'/60 0'8639 Bromine atoms of the said alkyl aromatic hydrocarbon is from 12 ZContains 15% to 25% by weight of dlnonyl naphthalene. to 40, and n ul ifi r th fo 50/50 Pamfiimc/Naphthemc SUS M 100 2. The lubricant of claim 1, wherein the number of Example 3 alkyl groups is 1 to 2. An oil-in-water emulsion is produced by combining g i l 1 wherem the alkyl groups con am 0 car 0 0 er 1 part by welght of an equal'welght fixture of 9 4. The lubricant of cl ain i whi r iir the alkyl aromatic of with 8 parts by weight of water. The resultin emulsion g fi g fif 2:52: 2 i fii gii z g ffig 0 math: gsnoassatrsfactory lubricant for cold-rolllng aluminum hydrocarbon is dodecyl benzene.

y EX 1 4 6. The lubricant of claim 1 wherein the alkyl aromatic amp e hydrocarbon is monononyl naphthalene. A l i i prepared i a manner i il to the 5 7. The lubricant of claim 1, wherein the concentration water-in-oil emulsion of Example 2. In this case the base of Water 15 5 to fluid Contains 80% by weight of monononyl naphthal 8. The lubricant of claim 1, wherein the concentration and 20% by weight of a paraffinic solvent-refined mineral of Water 18 0 t0 9 oil. The emulsifier package and the water concentration The lubl'fcant Ole-Clam 4, wherein the alkyl aromatic are the same as that of Example 2. The resulting emulsion hydrocarbon 15 a mlXtuTe of alkyl benzene and alkyl is a satisfactory lubricant for metal-rolling operations. naphthalene- Several emulsions of this invention are tested in the lubricant of claim wherein from 0 3 internal thread forming test described in detail in the a liy Welght of the alkyl aromatic hydrocarbon is re laced PP p cation Serial Number 639,665, filed on May 19, 1967, in by a mineral oil. the name of Robert H. Davis. These tests are shown in 11. The lubricant of claim 10, wherein the alkyl aro- 4 the said application to simulate stresses met during the actual metal-rolling operations.

Example 5 A number of oil-in-water emulsions are prepared by 5 6 matic hydrocarbon is a mixture of alkyl benzene and alkyl FOREIGN PATENTS naphthalene 892565 3/1962 G tB 't 12. The method of cold-rolling aluminum comprising tea n am using as the rolling lubricant an oil-in-water emulsion OTHER REFERENCES containing from 50% to 90% by weight of composition 5 Kobe], Chemical Abstracts, vol. 44 (1950), pages of water, wherein the oil portion consists of the alkyl 2217 d 2218,

aromatic hydrocarbon of claim 1 and all emulsifier Sachanen, Chemical Constituents of Petroleum, Reintherefor. hold Pub. Corp., 1945, pages 228, 229, and 233 to 240.

References Cited UNITED STATES PATENTS 10 DANIEL E. WYMAN, Primary Examiner. 2,447,475 8/1948 Kaberg et al. 252 312 XR CANNON, Assistant Examiner- 2,626,242 1/1953 Talley et a1 25259 XR US. Cl. X.R.

2,826,549 3/1958 Manteufiel et a1. 25249.5 XR 25259 3,310,489 3/ 1967 Davis 1252-495 15 

